Blowpipe



May 16, 1944. c. c. ANTHES BLOWPIPE Filed Aug. 5, 1940 INVENTOR fCLIFFORD C. ANTHES ATTORNEY l I ml i Patented May 16, 1944 BLOWPIPEClifford C. Anthes, Union, N. j., assignor to Union Carbide and CarbonCorporation, a corporation of New York Application August 3, '1940,Serial No. 350,177

4 Claims.

This invention relates to blowpipes for mixing gases, such as acetyleneand oxygen, and for discharging a combustible mixture of such gases toproduce flames for use in heating, welding, and cutting metals. Theinvention more particularly relates to means for securing injector meansWithin the gas-mixing tube of a blowpipe.

Blowpipes usually consist of several members which are detachablysecured to one another in order to facilitate manufacture, repair,inspection, and use thereof. A set of interchangeable tips and gasmixers of different sizes is usually supplied with each blowpipe so thatit may be provided and used with the proper size tip and mixer todeliver the `volume of mixed gas necessary to perform different kinds ofWork, e. g., for welding different thickness of metal, or for cut-v tingdifferent metals.

Such blowpipes usually include injector means disposed within agas-mixing tube or similar member for mixing the gases which are to bedischarged from the blowpipe. The injector means usually has circularwalls and is provided with seating surfaces which cooperate withcorresponding seating surfaces formed in the internal circular Walls ofthe gas-mixing tube so as to produce gas-tight joints when the injectormeans is secured within the gas-mixing tube. Heretofore, the injectormeans preferably has been detachably secured within the gas-mixing tubeby a toroidal snap ring seated in a circular groove formed in aninternal wall of the tube and acting against a protuberance formed onthe injector means, or by a toroidal snap ring seated in a circulargroove formed in a circular Wall surface of the injector means andbearing against an internal wall of the gas-mixing tube. This type ofconstruction has numerous advantages compared with other types ofconstruction. such as a threaded connection, but it permits the injectormeans to move rotatively and laterally Within the mixing tube when theblowpipe is jarred or moved violently. As a result of such movement, theseating surfaces on the injector means and on the walls of the mixingtube become Worn and the injector means becomes loose within the ltuberesulting in impaired operation of the injector means and consequentimproper gas mixing and flame production.

Furthermore, with the type of construction in which a toroidal snap ringis utilized for securing the injector means within the gas-mixing tube,a large proportion of the surface of the snap ring contacts the grooveor protuberance in which or against which the ring is seated.Consequently,

(Cl. S-27.4)

' when it is necessary to remove the injector means from the mixingtube, the relatively large frictional :forces developed between thesurfaces of the toroidal snap ring and the surfaces contacted by thering, impede such removal.

To overcome these difculties, securing means has been devised forholding an injector means within a gas-mixing tube so that the injectormeans is locked in position with respect to the walls of the tube,thereby substantially preventing rotation of the injector meansA Withinthe tube. The securing\means has been designed also to reduce to aminimum the area of contact between its surfaces and the surfaces of thegasmxing tube which it engages as the injector means is being withdrawnfrom the tube, thus facilitating the removal of the injector means fromthe tube when necessary.

Accordingly, the principal objects of this invention are: to providesecuring means for locking an injector means within a. gas-mixing tubeso that movement of the injector means within the tube is substantiallyprevented; to provide such securing means which is so designed as topermit ready dismantling and assembling of the injector means and thegas-mixing tube; and to provide a blowpipe in which the seating surfacesand joints between the various members of the blowpipe, and particularlybetween the injector means and the walls of the gas-mixing tube Will bemaintained in an accurate gas-tight condition for a longer time than hasheretofore been possible. provide resilient key means for locking amember having circular Walls within a chamber which has circular walls,so as substantially to prevent movement of the member relatively to thewalls of the chamber.

These and other objects and novel features of the invention will becomeapparent from the following description and the accompanying drawing, inwhich:

Fig. 1 is a longitudinal sectional view, partly in elevation, of ablowpipe embodying this invention;

Fig. 2 is an enlarged longitudinal sectional view of that portion of theblowpipe shown in Fig. l which contains the gas-mixing tube and injectormeans, and

Fig. 3 is an enlarged elevational view of a snap ring for locking theinjector means Within the gasmixing tube.

For purposes of description the invention is herein disclo ed inconjunction with 4a welding blowpipe, alt ough the principles may beapplied A further object of this invention is to chambers I2 and I3.

equally well to other types of blowpipes and to other apparatus in whichit is desired to secure telescoped members one within another in lockedposition, but so` that the members may be readily dismantled andassembled. For convenience in the following description, the termacetylene" will be used to denote any suitable combustible gas, and theterm "oxygen Will be used to denote any suitable combustion-supportinggas.

Referring to Fig. 1 of the drawing, the invention is shown as embodiedin a welding blowpipe including a tip assembly T, a stem assembly S, aninjector means I, a handle member H, and the valve block V. A gas-mixingtube M, having a gas-mixing chamber C at one end and a gasmixturepassage I leading therefrom to the other end is securely fixed withinthe stem `assembly S. These members may be joined in any suitable manneras by means of threaded connections. but the injector means I ispreferably secured Within the gas-mixing chamber C by means of asubstantially symmetrical polygonal snap ring 2 which is adapted to fitinto cooperating grooves 3 and 4 correspondingly located respectively inthe circular walls of the chamber C and the injector means I.

The usual nipples, valves, and conduits are provided for conductingrequired amounts of oxygen and acetylene respectively, to conduits 5 and6 which terminate in gas-tight connections 1 and 8 in a forward block 9formed integral with the handle member H and provided with passages Iand II for conducting the gases into the The injector means or aspiratorI has a unitary body, centrally and longitudinally through which anannular oxygen passage I4 is provided. A plurality of smaller annularacetylene passages I5, spaced radially around the oxygen passage I4, areformed in an enlargement I6 of the unitary body. The rear of the mixingtube M has a flange I1 against which a corresponding flange I8 formed onthe enlargement I6, is adapted to seat in a gas-tight manner. Othergas-tight joints I9 are provided by other cooperating seating surfaceson the injector means I and on the walls of the chamber C and surfacesof the member 9.

Passage 20, which is defined by the several surfaces of the forwardportions of the injector means I and the walls of the chamber C, permitsacetylene to be aspirated from the chambers I3 through the passages I byinjection action of the oxygen flowing through passage I4 and out of thetip 2| of the injector means I. This injection action results inthorough mixing of the voxygen andI acetylene within the mixing tube M,from which the mixed gases are discharged through the gas-mixturepassage I, the stem S and the tip T.

As shown in Fig. 2 a beveled circular groove 3 is formed in a wallof'the chamber C, and a circular groove 4 is formed in a surface of theinjector means I in a position correiponding to that of the groove 3.The snap ring 2, which is shown in Fig. 3 is of substantially hexagonalform, although it may be of other substantially polygonal forms. and isadapted to be seated in the groove 4. The injector means I and themixing tube M may be 'assembled by seating and compressing the snap ring2 into the groove 4 and then inserting the injector means I containingthe snap ring 2 into the chamber C until the flanges I1 and I8 meet.When the fianges I1 and I8 are in contact, the groove 4 registers withthe groove 3 and the snap ring 2 may then expand. Portions of the ring2, including. the I corners 22 are adapted to project into the groove 3,thus securing members I and M together. As will be evident, ring 2 willcontact the inner surface of groove 3 at a plurality of points spacedsubstantially equidistantly around the periphery of the groove 3, andwill contact the bottom surface of groove 4 at a plurality of pointsalso spaced substantially equidistantly around the periphery ofthegroove 4, but located between the points of contact with the surfaceof groove 3. Because of the polygonal form of the snap ring, theinjector means is substantially prevented from rotating or otherwisemoving within the mixing tube even though the blowpipe is jarred ormoved violently. f More specifically, the tube M has at one'end, asshown in Fig. 2, an internal annular seat 25, a frusta-conical camsurface 26 extending inwardly and forwardly from the seat 25,`and acylindrical surface 21 of constant diameter extending forwardly from thecam surface 26, to the annular groove 3. The groove 3 has afrusto-conical cam surface 28 extending outwardly and forwardly from thecylindrical surface 21 and an annular wall 29 extending in wardly fromthe cam surface 28. The tube M also has a cylindrical surface 30 ofconstant diameter which extends forwardly from the wall 29, afrusto-conical surface 3I extending inwardly and forwardly from thecylindrical surface 30, a cylindrical surface 32 of constant diameterextending forwardly from the frusto-conical surface 3|, and afrusto-conical surface 33 extending inwardly and forwardly from thecylindrical surface 32. The unitary body I is in the form of a plughaving an annular shoulder 34 fitting the internal annular seat 25, acylindrical surface 35 of constant diameter extending from the shoulder34 tothe annular groove 4 and fitting the corresponding surface 21 ofthe tube M. The annular groove 4 has parallel side walls 36 and 31 theforward one 31 of which is in a plane containing the wall 29 of thegroove 3 in the tube M. The body I also has a cylindrical surface 38 ofcontant diameter extending from the wall 31 and terminating at 39 inspaced relation to the forward end 40 of the corresponding cylindricalsurface 30 of the tube M. The plug I is provided with a nozzle 4I havingits outer surface 42 spaced from the inside of the tube M to provide anannular gas distributing chamber 43, the nozzle 4I having a cylindricalouter surface 42 of constant diameter spaced from the correspondinginner surface 32 of the tube M to provide a cylindrical gas passage 45extending forwardly from the chamber 43. The nozzle 4I has afrusto-conical end portion 46 spaced from the correspondingfrusto-conical inner surface 33 of the tube M to provide afrusto-conical gas passage 41 extending from the cylindrical gas passage45. The axial gas passage I4 extends through the plug I and through thenozzle 4I to the tip 2| of the latter. The longitudinal gas passage I5also extend through the plug I but open to the gas distributing chamber43. In spite of the fitting surfaces between the plug I and the tube M,the plug is incidentally subject to undesirable rotary and lateralmovement with respect to the tube M. Such movement is inhibitedaccording to the present invention by the polygonal split spring ring 2which fits the groove tween the tube M and the plug I, the arrangementbeing such that the plug I and the spring f/y ring 2 may be inserted inand withdrawn from the tube M without damage to any of the parts.

The assembled gas-mixing tube and injector means may be connected to thehandle member H by a coupling nut 23 having threads for engagingcorresponding threads on a flange portion of the member 9. By tighteningthe coupling nut 23, the seating surfaces i9 are brought togetherfirmly. The nut 23 is held in its tightcned position by a snap ring 24seated in a circular groove formed in the external wall of the mixingtube M.

To dismantle the members I and M after the nut 23 has been removed fromthe member 9. it is necessary only to pull the injector means I out ofthe chamber C by hand. since the beveled surface of the groove? directsthe snap-ring 2 into the groove 4 as pulling force is applied to theinjector means. The polygonal form of the snap ring facilitates thedismantling and assembling of the injector means and mixing tube,because when the ring is compressed within the groove 4 only smallportions of the surface of the snap ring are in contact with wallsurfaces of the gas-mixing chamber, thus reducing the friction betweenthe ring and such surfaces to a minimum.

The invention has been described in connection with a blowpipe, butother applications will readily suggest themselves to those skilled inthe art and other forms of snap rings or spring members than thatdisclosed herein may be employed without departing from the spirit andscooe of the invention.

What is claimed is:

1. A blowpipe comprising. in combination. a tube having at one end acylindrical surface of constant diameter extending forwardly from saidend, an annular groove having a frusto-conical cam surface extendingoutwardly and forwardly from said cylindrical surface and an annularwall extending inwardly from said last-named cam surface. a cylindricalsurface of constant diameter extending forwardly from said wall. afrusto-conical surface extending inwardlv and forwardly from saidlast-named cylindrical surface, a cylindrical surface of constantdiameter extending forwardly from said last-named frustoconical surface,and a frusto-conieal surface extending inwardly and forwardly from saidlastnamed cylindrical surface: a plug having a cylindrical surface ofconstant diameter tting the corresponding surface of said tube. anannular groove having parallel side walls the forward one of which is ina plane containing the wall of said groove in said tube, a cylindricalsurfer-e of constant diameter extending from said wall an'i terminatingin spaced relation to the forward eni of the corresponding cylindricalsurface of said tube, a nozzle having its outer surface spa-cel from theinside of said tube to provide an annuer gas distributing chamber, saidnozzle havingr 'i cylindrical outer surface of constant diameter spacedfrom the corresponding inner sur'ace rt said tube to provide acylindrical gas passage extending forwardly from said chamber. saidnozzle also having a frusto-conical end portion spaced from thecorresponding frusto-conical inner surface of said tube to provide a.fr'istouting chamber; said plug being incidentally subject toundesirable rotary and lateral movement with respect to said tube; andmeans for inhibiting such movement comprising a polygonal split springring fitting said grooves so as to inhibit relative movement betweensaid tube and said plug; the arrangement being such that said plug andspring vring may be withdrawn from said tube without damage to any ofthe parts.

2. A blowpipe comprising, in combination, a tube having at one end aninternal annular seat, frusto-conical cam surface extending inwardly andforwardly fromsaid seat, a cylindrical surface of constant diameterextending forwardly from said cam surface, an annular groove having afrusto-conical cam surface extending outwardly and forwardly from saidcylindrical surface andv an annular wall extending inwardly from saidlast-named cam surface, a cylindrical surface of constant diameterextending forwardly from said Wall, a frusto-conical surface extendinginwardly and forwardly from said last-named cylindrical surface, acylindrical surface of constant diam` eter extending forwardly from saidlast-named frusto-conical surface, and a frusto-conical surfaceextending inwardly and forwardly from said last-named cylindricalsurface; a plug having an annular shoulder fitting said internal annularseat, a cylindrical surface of constant diameter extending from saidshoulder and fitting the corresponding surface of said tube, an annulargroove having parallel side walls the forward one of which is in a planecontaining the wall of said groove in said tube, a cylindrical surfaceof constant diameter extending from said wall and terminating in spacedrelation to the forward end of the corresponding cylindrical surface ofsaid tube, a nozzle having its outer surface spaced from the inside ofsaid tube to provide an annular gas distributing chamber, said nozzlehaving a cylindrical outer surface of constant diameter spaced from thecorresponding inner surface of said tube to provide a cylindrical gaspassage extending forwardly from said chamber, said nozzle also having afrusto-conical end portion spaced from the corresponding conical gaspassage extending from said cylinfrusto-conical inner surface of saidtube to provide a gas passage extending from said cylindrical gaspassage; said tube having an axial -gas passage extending therethroughand through said nozzle: said tube also having a plurality of portionand successive adjoining portions of reduced diameter alternatelyfrusto-conical and cylindrical; and an insert comprising a plug ttingsaid long cylindrical surface and a nozzle corresponding to one of saidfrusto-conical surfaces; the front end of said plug and -the rear wardlyand outwardly inclined cam surface; and a polygonal split spring ringfitting said grooves so as to inhibit relative movement between saidtube and saidplug; the arrangement being such that said plug and springring may be withdrawn from said tube without damage to any of theparts..

4. In a blowpipe, a tube having a cylindrical bore of constant diameter,said surface having intermediate its ends an annular groove having afrusto-conical cam surface extending outwardly and forwardly and anannular wall extending inwardly from said last-named cam surface, saidtube having alternately frusto-conical surfaces and cylindrical surfacesof decreasing diameter extending from said cylindrical bore; a plughaving an external surface fitting said bore and an annular grooveregistering with the tube groove,`

and said plug terminating in spaced relation to "the forward end or thecorresponding cylindrical surface of said tube, a nozzle having itsouter surface spaced from the inside of said tube to provide an annulargas distributing chamber, a cylindrical gas passage extending forwardlyfrom said chamber, and a frustc-conical gas passage extending from saidcylindrical gas passage; said tube having an axial gas passage extendingthrough said nozzle and a plurality of gas passages opening to saiddistributing chamber; said plug being incidentally subject toundesirable movement with respect to said tube; and means for inhibitingsuch movement comprising a polygonal spring ring iltting said grooves soas to inhibit relative movement between said tube and said plug; thearrangement being such that said plug and spring ring may be withdrawnfrom said tube without damage to any of the parts.

CLIFFORD C. ANTHES.

